Digging through boxes that nobody else bothers to dig in. It's all perseverance, man. Just keep looking.
I agree with that statement 100%. If you have multiple ways of finding comics or mags, you'll maximize your chances of finding some of the great stuff. When I lived in Illinois, I worked with a guy and we talked about comics a lot. When I'd tell him about some of my buys, he'd say "You could fall into a pile of chit and come out smelling like a bed of roses.". And I would always say "No, I just work at optimizing my opportunities."
I look for comics and magazines at garage sales, flea markets, estate sales, local comic shops, on Craigslist, in online auctions, on eBay and elsewhere. Just like anything else, it's a lot of work but also kind of a mindset. Just maximize your opportunities and the good stuff will come around at some point. (thumbs u